Dissociation dynamics of in field-ion microscopy

Abstract

We investigate the dissociative quantum dynamics of the (Formula presented) ion field evaporated from a rhodium tip in field-ion microscopy. Numerical predictions of isotope effects, rotational, and vibrational times of this molecular ion are consistent with the experimental observations. Calculated dissociation field thresholds compared to classical results suggest the importance of the orientational tunneling in the ion dissociation process. Quantum calculations also reveal that dissociation dynamics takes place mainly via rotational and vibrational excitations of the ion and often through the quasibound states supported by the effective interaction potential of the ion. Furthermore, the time-of-flight spectra reveal fine structure associated with vibrational and rotational excitations, which should be observable using high resolution detectors. Show more